Network O/S

1
Network O/S

• Chapter 9 Lecture 1

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Network OS

• A network requires both a network operating
  system and client operating systems.
• Provides services to the clients
• Authentication
• File and print services
• Web server services
• Firewall and proxy services
• DHCP and DNS

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Network OS Options

• Windows NT/2000/XP/.Net
• Novell Netware
• Unix
• Linux
• Macintosh

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Selection Factors to Consider

• Hardware compatibility
• Technical capabilities
• Application support
• Budget
• Technical support

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OS Utilities

• Authentication
• File and print services
• Application support
• Security
• User-level security
• Rights given to certain users
• Share-level security
• Passwords assigned to resources (files, folders,
  printers)

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Windows NT

• Server
• Workstation (client)
• Scaled down version of server
• Purpose security and reliability
• Network Neighborhood

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Windows NT Domain or Workgroup Model

• Logical groups of computers
• Workgroups
• Small networks (lt10 computers)
• No network server
• Each computer can provide/use services to/from
  others
• Security database on each computer
• Must be updated on each computer
• Domain
• Centralized database of users
• Common administration

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WinNT Domain Model Contd

• PDC Primary domain controller
• Managing the network resources
• User database (authentication)
• Only one
• If it goes off-line, users cannot access the
  network
• No fault-tolerance
• BDC Back-up domain controller
• Contains a copy of the user database (updated
  periodically)
• Can be upgraded to PDC if PDC goes down
• Provides fault-tolerance
• Can have one or more BDCs
• Member Server
• File, Print, or Application services only

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WinNT 4 File Systems

• FAT File Allocation Table
• Index of file locations (clusters) on the disk
• ltWin95 r1 and DOS
• Can be upgraded to NTFS but not reversed
• NTFS new technology file system
• Supports very large files
• Supports long file names
• Provides file-level security
• Can not be downgraded to FAT

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WinNT 4 Monitoring Tools

• Performance Monitor
• View performance statistics of resources
• Amount of free memory
• Amount of virtual memory in use
• Amount of processor usage
• Amount of disk time (reads and writes)
• Amount of disk queue
• Network Monitor
• Capture and analyze network statistics
• View packet-level traffic to/from the server
• Task Manager
• Monitor applications, processes, and their
  performance/state
• End processes
• Event Viewer
• Allows the administrator to view
• Security Log
• Login Attempts/Failures
• Application Log
• Problems with apps

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WinNT User Manager

• Create and edit accounts
• Specify user permissions
• Create groups
• BCAS
• IT Faculty
• Special account administrator
• Group administrators

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WinNT 4 Network Settings

• Manage network settings
• Configure protocols
• Manage NICs
• Install services

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WinNT Authentication

• User logs in with username and password
• Server compares data with the user database
  including restrictions
• If valid, generates token providing permission
• Token contains userid in numeric format (SID)
  and group membership

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WinNT File Print Services

• Sharing
• Giving permission for one or more users to access
  the folder or printer and the permissions at the
  share read/write/full
• FAT
• Folder, subfolders, and files at the share level
  and below are accessible
• NTFS
• Can specify all the way to the file level what is
  shared
• Share name does not have to be the folder
  name/printer name

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Applications Support

• DHCP
• DNS
• IIS (web server)
• RAS
• etc

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Security

• Object-based security
• Specific devices
• User authentication
• Single sign-on (authenticate once and access any
  resource to which user has permission)
• Username is NOT case sensitive
• Password IS case sensitive
• File/directory security
• Folder and file level sharing